Traction-wheel.



PATENTED SEPT. 13, 1904.

' W. D. GOTTRELL.

TRACTION WHEEL.

APPLIOATION FILED NOV. 2, 1903.

N0 MODEL.

Witnesses proved traction-wheel.

NITED STATES Patented September 13, 1904.

PATENT Orrrcrj.

TRACTION-WHEEL.

SPECIFICATION forming part of Letters Patent No. 769,789, datedSeptember 13, 1904. Application filed November 2, 1903. erial No.179,493- (No model.)

To (LZZ whom, it may concern.-

Be it known that I, WARREN D. CoTTRnLL, a citizen of the United States,residing at Laurens, in the county of Pocahontas and State of Iowa, haveinvented certain new and useful Improvements in Traction-VVheels, ofwhich the following is a specification.

The objects of my invention are to provide a traction-wheel having onits tread portion ribs and tapered grooves so arranged that whentraveling over soft or yielding earth or snow the ribs will engage thesurface in such manner as to prevent the wheel from slipping eithercircumferentially or laterally and the grooves between the ribs willcause the soft or yielding earth or snow to be pushed laterally in bothdirections from the center of the wheel to thereby prevent earth or snowfrom filling up the grooves and adhering to the tread of the wheel.

A further object is to provide a wheel of this class in which the treadportions of the ribs present a flat surface, so that when the wheel istraveling over a hard road or a fiat floor the weight of the wheel willbe distributed over the entire treadportion; and a further object is toso arrange the ribs as to give a maximum of strength to the wheel-rim.

My invention consists in the construction, arrangement, and combinationof the ribs and tapered grooves on the tread portion of the wheelwhereby the objects contemplated are attained, as hereinafter more fullyset forth, pointed out in my claim, and illustrated in the accompanyingdrawings, in which- Figure 1 shows a side elevation of my im- Fig. 2shows an edge view of same. Fig. 3 shows a transverse sectional view onthe indicated line 3 3 of Fig. 2. Fig. 4c shows an edge view of amodified form of the wheel, and Fig. 5 shows an enlarged sectional Viewon the indicated line 5 5 of Fig. 4.

The reference-numeral 13 indicates the wheel-rim, preferably castintegral with the ribs 12. i In its periphery or tread portion I haveprovided a series of ribs 14:, extending from one edge of the rim in adiagonal direction to the centerof the rim, at which point it uniteswith a rib 15, extending completely around the wheel, on the treadportion thereof, and in the center of the rim. The outer faces of theribs 1%]: are flat and parallel with the hub 10, so that when the wheelrests upon a fiat surface the entire outer faces of the lower ribs willrest upon the fiat surface. Furthermore, the ribs 14 on one side of thecentral rib are staggered with relation to those on the other side, andthe ribs on one side join with the central rib 15 at points midwaybetween the points where the ribs on the other side join with saidcentral rib 15. Between each pair of the ribs 14 is a tapered groove 16,the maximum depth of said groove being greatest mum at the center of therim. In other words,

.the bottom of the groove 16 is inclined and curved to meet the top ofthe central rib 15, as clearly shown in Fig. 3. These grooves 16 aredeepest along their longitudinal center, and the bottoms of the groovesare curved gradually and uniformly toward the tops of the adjacent ribs14:, as clearly shown in Fig. 1.

In practical use with my improved form of traction-wheel and assumingthat the wheel is passed over soft or yielding earth or snow andassuming the wheel to be rotated in the direction indicated by the arrowin Fig. 2 it is obvious that said ribs will tend to prevent the wheelfrom slipping relative to the surface on which it is traveled eithercircumferentially or laterally, as the said ribs form substantiallyV-shaped figures on the surface over which the wheel is rolling. Theribs 14L by projecting from the face of the wheel cut into the surfaceover which the wheel is passing and prevent circumferential slipping,while the inclined portions of the ribs, together with the central rib15, both tend to prevent lateral slipping of the wheel. However, if thebottoms of the grooves between the ribs were of the same depththroughout the entire width of the rim then there would be a tendencyfor the soft earth or snow to fill up the spaces between ribs and packtightly therein, thus supporting the weight of the wheel upon the softearth or snow in said grooves and preventing the ribs from penetratingthe surface. To avoid this difiiculty, I have tapered the bottoms of thegrooves from a maximum depth at their outer ends to a minimum where theyjoin the central rib 15, so that the weight of the wheel pressingdownwardly upon the soft or yielding earth or snow tends to force thatportion of the earth or snow in said grooves toward the outer edges ofthe wheel, thus making the wheel self clearing and preventing earth andsnow from filling up the grooves and from adhering to the tread portionof the wheel. The tapered bottoms of the grooves 16 also aid inpreventing lateral movements of the wheel, as they provide a lateralpressure upon the wheel which is equalized on both sides of thewheel-rim, the tendency on each side being to force the wheel toward theside opposite. By arranging the ribs and grooves in staggered positionsI gain an additional advantage in that the central portions of thebottoms of the grooves may extend to a central line on the wheel, and atthe same time a central rib is provided. If the ribs 1 1 on oppositesides join at their inner ends, then of course the width of the centralrib 15 would prevent the bottoms of the grooves from reaching anapproximately central line around the periphery of the wheel. In theevent that pieces of soft earth or mud containing grass or roots shouldbecome lodged in the grooves 16 and extend across the entire face of thewheel then the central rib is of material advantage in that the grass orroots passing from one of the grooves 16 to the adjacent groove on theopposite side would be cut off by the pressure of said central rib 15upon the earths surface as the wheel revolves, and then the portions ofthe mass of earth could be forced outwardly from both sides of thewheel-rim after the grass or roots in the center had become severed bysaid rib.

In the modified form shown in Fig. 4 of the drawings I have illustrateda wheel-rim having a central rib 17 extending around the periphery ofthe wheel and a number of transverse ribs 18 at right angles to thecentral rib 17 The ribs 18 on opposite sides of the central rim are instaggered positions and the groove 19 between each pair of ribs 18 istapered from a maximum at its outer end to a minimumwvhere it. joins thecentral rib 17. This construction is clearly shown in Figs. 1 and 5, andin practical use the tapered bottoms of the grooves serve the samefunction as in my preferred form before described.

Having thus described my invention, what 1 claim, and desire to secureby Letters Patent of the United States therefor, is

An improved traction-wheel, comprising a rim, a rib extendingcircumferentially around the center of the rim, ribs extending from thecentral rib outwardly to the edges of the rim, the outer faces of all ofsaid ribs flush and parallel with the axis of the wheel, said rim formedwith tapered recesses between the outwardly-projecting ribs deepest andwidest at the edges of the rim and gradually curved to meet the top ofthe central rim, said recesses also curved to meet the tops of theadjacent outwardly-extended ribs.

WARREN D. OOTTRELL.

Witnesses:

B. L. SAUM, WM. HILSSON.

